1. Field of the Invention
The present invention relates to a flight control system for an aircraft.
2. Description of Related Art
Air to air combat may include a number of turns and maneuvers. There is typically a tactical advantage by having a higher velocity than the opponent. Higher velocities can be more readily attained by conserving energy during the various turns and maneuvers.
FIG. 1 shows a turn rate versus Mach number performance plot for a fighter aircraft. Starting at point A the fighter pilot may initiate a maximum performance turn by increasing the angle of attack (AOA) of the aircraft. The pilot increases the AOA until the fighter reaches the load limit of the aircraft at point B. At that point, the aircraft begins to slow down because of the additional drag created by the turn maneuver. The pilot continues an angle of attack so that the aircraft speed is at the load limit until the aircraft reaches the maximum turn rate ("corner speed") at point D. Between points D and E, and E and F the pilot maintains a maximum angle of attack to obtain the optimum turn rate.
To conserve energy it is desirable to control the fighter so that the aircraft does not reach the maximum turn rate (point D), but still has a relatively high average turn rate over time. For example, it may be desirable to have the fighter fly so that the aircraft performance curve follows the line between points C and E. During a combat engagement the pilot may not have the presence of mind, or the ability to monitor the bleed rate of the aircraft to obtain optimum energy conservation. It would therefore be desirable to have an aircraft control system that would automatically provide energy management for the plane.